This invention relates generally to monitoring animals and inanimate objects. More particularly the present invention is a form of electronic leash for animals and an electronic “tether” for portable objects carried by individuals.
Animals and portable objects share a common attribute: they can both be lost if care is not taken to be constantly aware of their location. For example, a household pet may quickly wander from its owner at a park or other area if not secured by a leash. A camera bag may be easily left at a restaurant if not secured by a shoulder strap or other “tether.”
In the field of animal training, various devices have been invented which are designed to keep animals within a confined area. For example the now ubiquitous “electronic fence” is seen everywhere as a means of keeping animals within a specific area. The electronic fence comprises a wire surrounding an area in which an animal is to be confined. An electronic current placed on the wire giving it a magnetic field and/or the wire is used as an RF transmitter. A collar is then attached to the animal which is capable of sensing the electronic field. When the strength of the electronic field is at a certain level, an audible warning is given to the animal. As the animal gets closer to the buried wire, an electronic shock is administered to the animal thereby providing a physical incentive for the animal to stay away from the buried electrical wire. Over a training period of time, the animal become becomes familiar with the meaning of the audible sound and the general location of the buried wire. In this fashion the animal is trained to stay within a confined area by virtue of the audible signal and the electronic shock in the event that the animal gets too close to the buried wire.
Much of the background art discloses animal collars and their circuitry, means for applying electrical shocks and audible stimuli to the animal worn device, a wide variety of “buried wire” systems together with associated stationary transmitters. Further, several instances of portable transmitters are also illustrated for control of GPS, and for allowing animal trainers to administer shocks to animals when desired. Much of the circuitry in the references cited will be known by those skilled in the art to be applicable to the present invention.
However, animal owners cannot carry a buried wire wherever they go. On the other hand, animals are enriched by being allowed to run free under the guidance of their owners. Diligence is required to be certain that the animal does become separated from its owner beyond a comfortable distance.
With respect to objects, such as cameras, key chains, purses, and the like, diligence is required to keep track of where an object is placed to be certain it is not left behind when the owner moves to another location. Diligence is also required to be certain that an object is not intentionally or accidentally taken by a third party. While mechanical tethers can be attached between objects and the owners of the objects, it is not always possible to leave these mechanical tethers in place while performing normal activities.
There have been several devices heretofore known that have attempted to solve the problem of locating lost or misplaced items. The following prior art devices relate to systems and devices for object finding: A product marketed as the Magnavox remote locater; a product marketed as the Brookstone SmartFind remote control key finder; U.S. Pat. Nos. 5,638,050 and 5,686,891 relating specifically to a locating system for a remote control having a “home base”; and U.S. Pat. Nos. 5,204,657; 5,648,757 and 5,790,021. These prior known devices have suffered from one or more of several deficiencies.
With one recent exception, previous devices are single-use devices where only one object could be located with the system. The one recent exception is the Brookstone product that allows users to locate up to two objects. This system will not allow the user to keep track of more than two items. Also, this product only provides for key chain attachment, and does not allow for a more permanent and secure attachment to a variety of other commonly misplaced items, such as remote-control devices, cell phones, PDA's, pagers, electronic devices, etc. This, product also suffers from the multiple system interference problem described below, and also does not provide any means to prevent the misplacement of the transmitter itself. U.S. Pat. No. 6,674,364 sought to remedy these deficiencies by providing means for locating multiple devices.
Finding an object requires there be some perception that the object is missing. In the case of valuable objects, the delay in perception may be costly. How many times does a person notice many hours later, that a purse or other object has been left at a store or restaurant ? By that time, the object may be out of range of the finding device, either because the owner has left the vicinity of the object or the object has been removed from the vicinity of the owner. Various attempts have been made to solve this problem using powered transmitters and powered receivers. U.S. Pat. No. 6,075,443 issued to Schepps for a “Wireless Tether” uses a transmitter-receiver pair to establish proximity between a detector and at least two transmitters. The patent describes issuing an alarm if the detector does not detect any of the monitored devices. Schepps does not teach or describe identifying which device is causing an alarm to be issued. Schepps further suffers from the need to power both the transmitter and the detector.
What would be truly useful would be a system that comprises an “electronic leash” or “electronic tether” which can be variably preset by an animal or object owner and operated so as to prevent the animal or object from becoming separated from its owner. Such a system would further be capable of identifying a specific animal or object that is missing from a group of monitored animals or objects.